Ancient sanctuary tied to 'most mysterious' cult uncovered in rare find beneath historic city

Its remnants were found ahead of a construction project involving multistory apartment buildings in Regensburg, officials said.

The City of Regensburg announced the discovery in early February.

The temple, built sometime during the first or second centuries A.D., was dedicated to Mithras, a deity from a "mystery cult" associated with light and cosmic order.

The official told Fox News Digital in a translated email that the find is "also unique in Bavaria."

Sebrich noted, "Based on the evaluation of the coins discovered in the sanctuary, it is the oldest of the nine known Mithras temples identified in Bavaria to date."

He said the Mithras cult spread from Asia Minor to Rome through cultural exchange. "Secret knowledge" was passed on to mystae - members of the cult - during rituals.

"As their knowledge increased, they could attain up to seven grades of initiation and thus ascend the celestial ladder toward the highest possible level of understanding," Sebrich said.

These rituals were documented in Regensburg, and the site contained drinking vessels, tableware and storage containers.

Archaeologists didn't realize the significance of the building until the post-excavation analysis, Sebrich said.

Though no cult image turned up during the early part of the excavation, Sebrich said "the special tableware, the overturned cabinet and the distinctive food remains provided numerous indications that it was a Mithraeum."

Later, archaeologists uncovered a silver votive plaque reading "DEO INVICTO" - a title only used for Mithras.

Only "selected individuals" could become members of the cult, Sebrich said, though it wasn't necessarily restricted by social class.

"In addition to soldiers, members included veterans, merchants, slaves and freedmen," he noted. "Women were generally excluded from membership."

Sebrich said the temple burned down in 171 A.D., as part of the Marcomannic Wars.

He added, "It is possible that undamaged altars or cult objects were salvaged from the fire debris and reused in the new sanctuaries."